Method of installing liner for thin wall pipe pile



F. RuscHE 3,418,817

METHOD OF INSTALLING LINER FOR THIN WALL PIPE PILE Dec. 31, 1968 INV ENTOR ATTORNEY Dec. 3l, 1968 F. RuscHE 3,418,817

METHOD 0F INSTALLING LINER FOR THIN WALL PIPE PILE Filed Sept. l2, 1967 Shee'l 2 of 2 FIGB ATTORNEY United States Patent O 3,418,817 METHOD F INSTALLING LINER FOR THIN WALL PIPE PILE Fredrc Rusche, 8125 Medina St., Detroit, Mich. 48217 Filed Sept. 12, 1967, Ser. No. 667,306 3 Claims. (Cl. 61--53.52)

ABSTRACT 0F THE DISCLOSURE A liner is placed in the lower portion of a thin wall pipe pile to maintain the roundness of the pile section and prevent collapse thereof during heavy driving. Ordinarily, a hole is wet drilled downwardly through earth to a bearing strata leaving the drilling mud in the hole. A thin wall pipe having a driving point is then forced down in the hole until the point reaches the bearing strata. Then the point is driven into the bearing strata by an inserted mandrel which engages both the point and the top of the pile. The mandrel has a lower expansible section which engages in a liner and an upper tubular non-expansible section which fits freely into the pile. The liner is carried down into the lower portion of the pile by the mandrel. After driving the pipe pile until its point penetrates the bearing strata, the mandrel is removed, leaving the liner in the lower end of the pile.

RELATED APPLICATION Rusche, Method for Driving Thin Wall Pipe Piles, Ser. No. 651,901, filed July 7, 1967.

Background of the invention Field-Hydraulic and earth engineering; stable structures in shifting media; piles, with installing; driving removable wall supporting core; diametrically retractable core.

Priori art.-Rusche 3,006,152 discloses an expansible mandrel generally similar to the lower section of the mandrel herein disclosed; Rusche 3,269,128 discloses the coupler used herein; and Rusche 3,283,519 discloses the impact pads used in the lower mandrel section herein.

OBJECT The object of this invention is to provide a method and means for installing a liner in the lower portion of a thin wall pipe pile which has been forced into a predrilled hole, without the necessity for excessively long leads or the use of a doodle hole. A more particular object is the provision of a mandrel which is capable of insertion into a pointed thin wall pipe pile so as to drive the point, as well as the top of the pile, while simultaneously installing a liner into the lower end of the pile.

The salient features of the invention are disclosed in the accompanying drawings, in which:

FIGS. 1a and 1b are a composite, vertical cross-section through the mandrel respectively showing the portions designated 1a and 1b in FIG. 3;

FIG. 2 is a fragmentary cross-section showing detail of one of the expanding plugs;

FIG. 3 is an elevational view of the mandrel shown in FIGS. la and lb installed in a thin wall pipe pile which is shown in vertical cross-section.

FIG. 4 is a diagrammatic cross-section illustrating the start of the wet pre-drilling of a hole;

FIG. 5 is a view comparable to FIG. 4, showing the installation of a thin wall pipe pile in the hole to the eX- tent that a driving point reaches a bearing strata;

FIG. 6 is a view comparable to FIGS. 4 and 5 illustrating the start of the installation of a liner into the lower end of the thin wall pipe pile;

3,418,817 Patented Dec. 31, 1968 FIG. 7 is a view comparable to FIGS. 4-6 illustrating the inal driving step of the thin wall pipe pile and the liner; and,

FIG. 8 is a view comparable to FIGS. 4-7 showing the driven thin wall pipe pile and liner filled with concrete.

Referring first to FIGS. 1a, 1b 2 and 3 of the drawings, the structure of mandrel 10 will iirst be described, utilizing like reference numerals to denote similar elements.

Mandrel 10 is formed of sections of different types and diameters, comprising at least one upper section 12 which is of larger diameter and non-expansible, and an expansible lower section 14 joined to the upper section by a coupler 16. Upper section 12 is composed basically of a heavy steel pipe 18 closed at its upper end -by a cap and plug 20 and provided near its top with a driving ring 22 and ears 24 for tying into the bonnet of a pile driver. A side tube 26 above ears 24 connects the hollow interior of pipe 18 with a suitable source of pressure fluid, such as compressed air. Across the lower end of pipe 18 is welded a plate 28 onto which is welded a hollow cylindrical skirt 30 having around its inner side an annular channel 32. Removable plugs 34 close openings 35. A hollow socket 36 on plate 28 has with the hollow interior of pipe 18 an aperture 38 which provides a connection.

Lower mandrel section 14 is essentially a hollow cylindrical tube 40 of heavy steel, which is of lesser diameter than pipe 18, and which has a driving plate 42 secured to its lower end. Near its upper end tube 40 has a plate 44 welded thereacross and to plate 44 is welded a hollow cylind-rical skirt 46 which, like skirt 30' on the upper mandrel section, has an annular internal channel 48 with through-wall openings 49 closed by plugs 50.

Semi-:Heating within tube 40 is a hollow central column 52 which terminates in a coupling socket 54 at its lower end. Unless the lower section 14 of the mandrel is to be coupled below to still another section, socket 54 is closed by a plug 55. At its upper end, column 52 terminates in a manifold 56 which has on its upper side a socket 58 whose function will be later described.

Along each of four sides of column 52 are inatable elongate bags 60, which may be formed of fire hose, and which are connected to the interior of manifold 56 via holes 62. Suitable coupling nipples, not shown, may be used for securing the bags to the manifold. Bags 60, when inated, press against plates 68 to which are secured shoes 70 by bolts 72. Shoes 70 are preferably exteriorly surfaced with suitable friction material 74, such as asbestos brake lining. As detailed in FIG. 2, sockets 76 in the faces of plates 68 receive ends of columnnar elastomeric compression springs 78 whose other ends engage in bores 80 through the lwall of tube 40. The outer ends of bores 80 are closed by screw plugs 82. Thus when pressure uid enters manifold 56, bags 60 expand and express shoes 70 radially outward beyond the surface of tube 40, and when the pressure fluid is released, springs 78 retract the shoes inwardly of the surface of tube 40.

Hollow central column 52 is floatingly mounted to its upper and lower ends by means of compression pads 84, 86. The upper end of manifold 56 has a bearing ring which bears against pads 84 which, in turn, bear against partition plate 44; and the lower end of the column has a bearing ring 87 which presses against pads 86 which, in turn, bear against driving plate 42. The parts are so dimensioned and assembled that pads 84, 86 pre-compressed Iare under considerable pressure when the lower section 14 is assembled. The slight floating motion of column 52 under the impact of heavy driving renders it virtually indestructable under heavy driving. These features are more fully described in Rusche 3,283,519.

Coupler 16 comprises a collar 88 integral with cylindrical bosses 90 and 91 which telescope into skirt 30 on the lower end of the upper mandrel section 12 and skirt 46 on the upper end of lower mandrel section 14. Annular grooves 92 in the bosses accommodate steel balls 93 which also engage in annular channels 32, 48 in skirts 30, 46 so that the mandrel sections are blocked against movement apart from one another. Locater apertures 94 in collar 88 receive the ends of locater studs 96 in skirts 30, 44 so that no relative rotation of the mandrel sections or coupler is permitted. The impact loads of driving are transmitted in compression by the butt engagement of skirts 30, 46 against collar 88.

Coupler 16 has an axial bore 98 through which first an air coupler tube 100 ywhich engages at its upper end into socket 36 and at its lower end into socket 58. Suitable seals 102, 104 are provided for the coupler tube ends to prevent air leakage. Thus, when pressure fluid enters via pipe 28 it is transmitted to manifold 56 via the hollow interior of pipe 18, aperture 38 in socket 36 to air coupler tube 100, through tube 100 to socket 58 and thence into manifold 56 so that shoes 70 are expressed. A coupler of this type is more fully described in Rusche 3,269,128.

FIG. 3 shows mandrel 10 as used during one of the driving steps diagrammatically illustrated in FIG. 7, wherein it is driving both a liner 106 and a thin wall pipe pile 108. Liner 106, it will be noted, is somewhat longer than the distance from-coupler 16 to the lower end of driving plate 42; and thin wall pipe pile 108 is somewhat longer than the distance between driving ring 22 and driving plate 42.

FIGS. 4-8 illustrate the method. A hole 120 is first wet-drilled by the bit 122 of a rotary drilling rig 124 down to a bearing strata 126, while leaving the drilling mud in the hole to prevent cave-in. FIG, 4 illustrates the wet drilling step partly completed. Then drill bit 122 is removed and driving point 110 is installed on the lower end of thin wall pipe pile 108. This is usually done by resting driving point 110 on a mat, raising thin wall pipe pile 108 in the leads of a pile driver, and lowering it onto the driving point 110 so that the lower end of the pipe pile is ared out over a tapered boss 114 on driving point 110. The joint between the pipe pile is sealed by a gasket ring 116 in a groove 118 in tapered boss 114. A light blow or two on the top of pipe pile 108 is enough to flare out its lower end over boss 114 until such lower end seats against a shoulder 112 on driving point 110. The particular connection shown between driving point 110 and pipe pile 108 is merely illustrative of other types which can be used.

Next, pipe pile 108 is then juxtaposed over hole 120, and then it is forced downwardly by hammer 130 until its driving point 110 reaches bearing strata 126. A few light blows of hammer 130 are suicient to force pipe pile 108 down into hole 120 while simultaneously forcing the drilling mud, which until this time has filled the hole, upwardly between the pipe pile and the side of the hole and out the top, all without the -necessity of suicient force to damage the thin wall of the pipe pile.

Next, ears 24 on mandrel 10 are connected to bonnett 128, hammer 130 is raised in the leads a sucient distance to raise the lower end of mandrel above the ground to permit installation of linear 106 over lower mandrel section 14, compressed air is admitted through pipe 26 to expend shoes 70 suiciently to provide a good expansive grip on linear 106, and the mandrel 10 with liner 106 is lowered downwardly (FIG. 6) into pipe pile 108 until the lower end of liner 106 engages tapered boss 114. A light blow or two by hammer 130 will flare out the lower end `of liner 10'6 around the upper end of tapered boss 114 until driving plate 42 engages the upper end of boss 114. Now the assembly is ready for final driving.

FIG. 7 illustrates the nal driving step. Blows by hammer 130 exert driving force both on driving point 110, because of engagement of driving plate 42 therewith, and also on the upper end of pipe pile 108, because of engagement of driving ring 22 therewith. Driving on the upper end of pipe pile 108 prevents mandrel 10 from forcing driving point 110 off the lower end of the pipe pile; and the gripping engagement of shoes 70 on liner 106, as well as the abutting engagement of coupler collar 88 on the upper end of liner 106, forces the liner downwardly with the pipe pile.

After bearing strata 126 has been penetrated sufficiently to provide good bearing for the pile, mandrel 10 is withdrawn, leaving the pipe pile and liner in place, and concrete 132 is then poured in to lcomplete the pile.

It should be noted that the cross-sectional thickness of the side walls of both the upper and lower mandrel sections, as well as the coupling, are greatly in excess of the thickness of the side wall of the pipe pile. This makes the mandrel only slightly compressible lengthwise so that most of the driving forces applied to cap 20 are applied directly to driving point 110. Pipe pile 108 is placed under endwise compression during driving, but the elastic stortening of the mandrel under driving is less than that of the pipe pile. Liner 106 ltakes very little of the driving forces. For purposes of the present example, it is assumed that if the upper mandrel section is about 12 inches in outer diameter, the wall thickness of both mandrel sections would be from 1.5 inches to 2.0 inches, while the wall thicknesses of the pipe pile and liner would be from about 0.125 inch to about 0.215 inch.

By utilizing the subject method and apparatus, it is possible to install a liner in the lower end only, where it is most needed, of a thin wall pipe pile; expense of superfluous liner material is saved; economies are achieved by the ability to utilize thin wall pipe without danger of damage by driving o-r by lateral forces in the earth; and the necessity for excessively high leads is avoided.

I claim:

1. The method of driving a thin wall pipe pile with a liner in the lower end thereof, comprising, wet-drilling a hole through earth downwardly to a bearing strata and leaving drilling mud in the hole after the wet drilling,

driving a thin wall pipe pile having a driving point on the lower end thereof downwardly into the hole until the driving point reaches the bearing strata and thereby forcing the drilling mud from the hole, inserting into the pipe pile -a mandrel having a liner of lesser length than the pipe pile engaged around the lower end thereof until the lower end of the mandrel reaches the driving point, driving both the pipe -pile and liner downwardly by means of hammer blows applied to the upper end of the mandrel until the driving point is seated home in the bearing strata,

and removing the mandrel from the pipe pile while leaving the liner in the lower end of the pipe pile.

2. In the method recited in claim 1, the subsequent step of lling the pipe pile and sleeve with concrete.

3. The method recited in claim 1, wherein the lower portion of the mandrel is expansibly engaged in said liner at the time the mandrel with the sleeve thereon is inserted into the pipe pile.

References Cited UNITED STATES PATENTS 1,742,926 1/1930 Newton 6l-53.66 3,006,152 lO/l96l Rusche 6l-53.72 3,187,5l3 6/1965 Guild `61-535 FOREIGN PATENTS 591,985 4/1959 Italy.

JACOB SHAPIRO, Primary Examiner. 

